This invention relates to the resolution of ambiguities associated with a plurality of targets within a spatial area monitored by a plurality of directional sensors.
At present, if an unknown number of targets exist within a spatial area which is monitored by a plurality of directional sensors at known positions, it is difficult to estimate the number and positions of those targets.
In an ideal case, if only the angle of arrival of tonal information from a target to a directional sensor can be determined, and if the tonal information can be detected in such a way by a plurality of directional sensors, then the position of that target can be found by the bearing intersection of the direction vectors, extending from each directional sensor at the angle of arrival of the tonal information.
However, in practice, propagation effects usually limit the number of targets detected at any one sensor, making it no longer possible to estimate the number and positions of multiple targets by simple examination of the bearing intersections.
A frequency line track is a tonal signal and associated parameters such as a bearing estimate (or an angle of arrival at a sensor), signal strength, frequency or bandwidth.